#include using namespace std; #include using namespace atcoder; using mint=modint998244353; //1000000007; using ll=long long; using pp=pair; #define sr string #define vc vector #define db double #define fi first #define se second #define rep(i,n) for(ll i=0;i<(ll)n;i++) #define pb push_back #define all(v) v.begin(),v.end() #define pque priority_queue #define bpc(a) __builtin_popcount(a) int main(){ ll n;cin>>n; //a*p+b/p*p-1; ll ans=0; rep(a,10)rep(b,10){ if(a==b)continue; ll ac=max(a,b),wa=n*10; while(wa-ac>1){ ll p=(ac+wa)/2; if(n*(a*p+b)>p*p-1)ac=p; else wa=p; } ans+=ac-max(a,b); } cout<